Spark plug



Patented `Feb. 4'119,

SPARK PLUG y Carl Elon Bernstrm, Stockholm, Sweden Application December 5, 1930, Serial No. 500,403

Y In Sweden February 11, 1929 3 Claims.

The present invention relates to a spark plug for use in internal combustion engines with electric ignition, said spark plug being provided with an air channel for the cleaning of the spark gap.

A spark plug according to this invention is shown in the accompanying drawing, in which Fig. 1 shows the whole spark plug in section and Fig. 2 part of it with a modiiied detail.

The outer electrode 1 is so shaped as to form a chamber 2 of a considerable extent around an insulating core 3 and a central electrode 4 located in the same. This central electrode is of such a construction that a spark gap 5 is obtained between the wings of a rotatable fan or wing-wheel 6, suitably mounted at the end of the electrode 4, and the outer electrode l of the spark plug. This electrode l constitutes the electrode connected to the ground, said electrode being at its lower part provided with a collar 8 running around the spark gap. 9 is a compression cock connected to the spark plug.

When the motor is working, a stream of gas surges to and fro'through the spark gap owing to the changes in pressure in the cylinder, said stream of gas being suiiicient to put the rotatable fan in motion and by this to prevent, to a certain extent, grime, oil and the like from being attached in the spark plug. When the compression cock 9 is open, the rotatable fan is rotated at a speed in proportion to the revolutions of the motor. Thus the spark plug is completely cleaned of all depositions of soot and oil which are thrown out through the compression cock 9. In this way the spark gap between the electrodes is always kept clean.

The cleaning of the spark plug can thus be effected by opening and shutting the compression cock when the motor works. In aircraft for 1nstance, this can be effected directly from the drivers cabin bymeans of a suitably arranged lever or the like.

The utility and durability of the spark plug are increased since the spark can come to one or several points at the same time and always changes its position on account of the motion of the rotatable fan. Further by this motion the formation of sparks becomes more lively and more intensive, so that the gas is easier to ignite.

Instead of locating the. rotatable fan on the central electrode said fan is adapted to be located on the outer electrode of the spark plug, as shown in Fig. 2. The fan is here shown journalled on a shaft l0, running straight across the lower part of the electrode. Through the shown position of the wings (I can also screen one half of the rotatable fan) a stream of gas passing through the chamber 2 can put the fan in motion.

As most modern motors are not provided with compression cocks a spark plug provided with such a compression cock has its obvious importance, for one can lead combustible liquid direct to the cylinder in order to facilitate the starting of the motor, especially in cold weather. To facilitate this priming and to get a suitable quantity into the cylinder when the compression cock is opened, the inlet of the same is widened into a hopper 12.

Having now described my claim as new and desire to secure by Letters Patent is:

1. A spark plug, comprising a fixed electrode; a movable electrode having uid reactive surfaces and spaced from the fixed electrode; a chamber communicating withV the space between the electrodes; and a valve for opening the chamber to the atmosphere, so that operation of the engine will force some of the gasesthrough the space and the chamber to move the movable electrode and remove depositions therefrom.

2. A spark plug as set forth in claim 1, wherein the movable electrode comprises a rotatable fan.

3. A spark plug for igniting gases in a combustion chamber of internal combustion engines comprisinga metallic casing forming an outer electrode, an insulating body within said casing, a central electrode extending axially through the casing and spaced therefrom by said insulating body, a fan freely rotatably mounted on the inner end of said central electrode, said casing having a port in the upper portion thereof,

a valve associated therewith to control communication between the interior of the casing and the atmosphere and to provide for the ow of gases from the combustion chamber over said fan to effect rotation thereof.

CARL ELoN BERNSTRM.

invention, what Iy 

